Social media is typically littered with pictures of pets. But you may have noticed an event on Facebook lately that many of your friends are planning to attend – and it involves posting pictures of your dogs.

If you have, don’t worry because you are not missing out on some cool party or happening pooch-friendly bash. What’s going on is the “Photo Doggies for Anthony” Facebook trend, an “event” page started by a family friend to help cheer up a 16-year old leukemia patient being treated at Phoenix Children’s Hospital in Arizona that’s causing most of our Facebook feeds lately to be even more crammed with pictures of dogs than usual.

The boy’s name is Anthony Lyons and he loves dogs. The problem is that Anthony’s dogs cannot accompany him when he receives treatment at the hospital, and therapy dogs are not always around either.

“Some days he gets doggy visits and some he does not. They make him smile,” the Lyons family friend wrote on the Photo Doggies for Anthony Facebook page. “I thought if I create this event, you can post a picture of your dog to help make him smile. His mom shows them to him and he smiles.”

The event is easy enough to participate in – all you have to do is join and upload a picture of your dog – and quickly went viral garnering over 1.4 million people attending as of 11 a.m. Thursday morning and another 455,000 invites.

“Anybody who has a dog or anybody who has kids just feels like ‘wow, this is a really easy way to give someone a smile,”' said Ronni Zimbler Newton, a West Hartford mom of two and dog owner who posted a photo of her dog Scarlett to the page Monday. "The more smiles you have, the better you feel and you probably feel like the world is rooting for you.”

If you’ve been on Facebook at any time during the past week you’ve probably seen a notification that one of your friends is attending or has posted a picture of their dog to the page, which is precisely why the page has become so popular says Rich Hanley, a journalism professor at Quinnipiac University who studies social media.

“It’s easy to do and once it gains a certain momentum then the network effect kicks in and exponentially races across social media,” Hanley said. “Folks are confronted with it in their feeds and it’s just easy to take part in.”

Anthony’s mom, Kristen Lyons, also uses the page to post updates on Anthony’s treatment and condition and thank those who have participated.

“I am amazed at how quickly this event has blown up and it makes me so happy to know how many people enjoy their pets as much as Anthony and I do. Your pets have brightened our days so much and it just shows you the power of pet therapy and animal healing. This just shows what great people animal lovers are and we are really feeling the love from you and your pets in this difficult time. Thank you all so much from the bottom of our hearts,” Kristen Lyons wrote.